Ah, it was not clear to me you're looking for the text operation only (not fetching from DB).
–
hakreJan 2 '12 at 8:08

No worries. I always fear I'm not making sense when I ask questions. I was pulling from the database, but I didn't want to open a whole 'nother loop since I have things like get_the_title($post->ID) available. The final line of code was $description = wp_trim_excerpt(get_post($post->ID)->post_content);
–
jlengJan 2 '12 at 19:56

That returns blank if no excerpt was entered for the post. I need to mimic the actions of get_the_excerpt() (creating an excerpt if none exists).
–
jlengDec 31 '11 at 19:00

Applying the filter won't do that, so you're asking the wrong question. No idea why you're looking for an excerpt if there isn't any. get_the_excerpt() does not mimic that, check the source, it's only accessing the member variable of $post which is post_excerpt. See also the codex link in the answer.
–
hakreDec 31 '11 at 19:11

From the Codex entry on the_excerpt: "it will display an automatic excerpt which refers to the first 55 words of the post's content." I'm looking to mimic that behavior outside of the loop.
–
jlengDec 31 '11 at 20:14

Thanks for the link. I knew I could set up an additional loop, but it seems like overkill. My solution was adding a filter. I see it as a little elbow grease now for a lot less code later.
–
jlengJan 1 '12 at 18:14